Characteristic Cochlear Hypoplasia in Patients with Walker-Warburg Syndrome: A Radiologic Study of the Inner Ear in α-Dystroglycan-Related Muscular Disorders.

BACKGROUND AND PURPOSE: Walker-Warburg syndrome, muscle-eye-brain disease, and Fukuyama congenital muscular dystrophy are α-dystroglycan-related muscular disorders associated with brain malformations and eye abnormalities in which no structural inner ear abnormality has been described radiologically. We collected patients from 6 tertiary pediatric hospitals and reported the radiologic features and frequency of inner ear dysplasias. MATERIALS AND METHODS: Patients previously diagnosed clinicoradiologically with Walker-Warburg syndrome, muscle-eye-brain disease, or Fukuyama congenital muscular dystrophy were included. We recorded the pathogenic variant, when available. Brain MR imaging and/or CT findings were reviewed in consensus, and inner ear anomalies were classified according to previous description in the literature. We then correlated the clinicoradiologic phenotype with the inner ear phenotype. RESULTS: Thirteen patients fulfilled the criteria for the Walker-Warburg syndrome phenotype, 8 for muscle-eye-brain disease, and 3 for Fukuyama congenital muscular dystrophy. A dysplastic cochlea was demonstrated in 17/24. The most frequent finding was a pronounced cochlear hypoplasia type 4 with a very small anteriorly offset turn beyond the normal-appearing basal turn (12/13 patients with Walker-Warburg syndrome and 1/11 with muscle-eye-brain disease or Fukuyama congenital muscular dystophy). Two of 8 patients with muscle-eye-brain disease, 1/3 with Fukuyama congenital muscular dystrophy, and 1/13 with Walker-Warburg syndrome showed a less severe cochlear hypoplasia type 4. The remaining patients without Walker-Warburg syndrome were healthy. The vestibule and lateral semicircular canals of all patients were normal. Cranial nerve VIII was present in all patients with diagnostic MR imaging. CONCLUSIONS: Most patients with the severe α-dystroglycanopathy Walker-Warburg syndrome phenotype have a highly characteristic cochlear hypoplasia type 4. Patients with the milder variants, muscle-eye-brain disease and Fukuyama congenital muscular dystrophy, more frequently have a normal cochlea or milder forms of hypoplasia.

Transverse dural sinuses: incidence of anatomical variants and flow artefacts with 2D time-of-flight MR venography at 1 Tesla.

PURPOSE: This study sought to identify imaging criteria useful in discriminating anatomical variants from thrombosis of the posterior intracranial venous system. MATERIALS AND METHODS: A total of 102 patients underwent coronal unenhanced two-dimensional time-of-flight (2D ToF) magnetic resonance (MR) venography. Transverse sinus (TS) calibre and asymmetry were considered. Oval (O-FG) and linear (L-FG) flow gaps were recorded. Several slices of the 2D ToF sequence were applied perpendicularly to the TS within each FG to avoid in-plane saturation. RESULTS: Mean calibre of the right TS was significantly greater than the contralateral sinus (6.5 mm+/-1.84 vs 5.1 mm+/-1.72). Right and left dominance was observed in 61% and 17% of cases, respectively. The mean right-left TS diameter was 5.77 mm. Among 204 TS, 44 L-FG and 42 O-FG were observed. Partial L-FG (<2/3 of TS) never involved the distal TS. No L-FG was observed in a dominant TS. Supplementary sagittal 2D ToF images disclosed blood flow in all but two L-FGs. O-FGs were mostly observed laterally (91%). CONCLUSIONS: L-FGs in a dominant TS, partial L-FGs in the distal part or O-FG in the medial part of any TS, a left-right mean diameter <3 mm and absence of flow even in ToF images perpendicular to the direction of blood flow should raise the suspicion of sinus pathology.